In a medium saucepan combine whipping cream, 1 cup of the milk, half of the sugar and the salt. Using a paring knife, cut the vanilla pods lengthwise and scrape out the tiny seeds; add to saucepan. Cook over medium heat until just below simmering point. Remove from heat. Cover and let stand 10 minutes to allow vanilla to infuse cream mixture.
While mixture is standing, prepare an ice water bath in a bowl large enough to set another bowl easily inside of it. Set aside.
For custard, in a medium bowl whisk to blend egg yolks and remaining sugar. Slowly whisk in 1 cup of the hot cream mixture; return cream mixture to saucepan. Cook over medium heat, stirring constantly with a rubber spatula until custard thickens enough to coat back of spatula. Remove from heat and stir in remaining milk.
Strain custard through a fine - mesh sieve into a stainless steel bowl set in the ice - water bath. Stir custard until cooled. Cover and refrigerate until thoroughly chilled or up to 48 hours before freezing.
To prepare nuts, preheat oven to 350 degrees F. Line a baking sheet with parchment paper. Toss pecans with melted butter and spread in a thin layer on prepared baking sheet. Drizzle honey over nuts and sprinkle with cinnamon and cayenne pepper. Use a wooden spoon to give a quick stir. Roast in oven for 4 to 6 minutes, stirring once halfway through. Cool on a wire rack.
When ready to freeze the ice cream, stir whiskey into custard. Transfer custard to ice cream canister. Freeze according to manufacturer's instructions. Stir in pecan mixture. If desired, ripen for at least 4 hours.